Trichogrammidae 501 



Only a single generation of Trichogramma may be reared on one 

 card of eggs, unless fresh eggs are added at the time the adult Tricho- 

 gramma are about to emerge. It is more convenient to use separate, 

 freshly prepared cards for each generation. 



Some strains reproduce readily in complete darkness, but as a rule 

 the maximum oviposition occurs in diffused daylight. At certain times 

 the adults are strongly positively phototropic and tend to leave the 

 vicinity of host eggs. Light is not necessary for oviposition, for the 

 writer has obtained tenfold reproduction in complete darkness. Under 

 certain conditions light may result in a decrease in reproduction. 



The life cycle of Trichogramma varies with the temperature, ranging 

 from 6 days at 90 F., to 80 days at 50 F. 



Glass vials, petri dishes inverted on plate glass, or mailing tubes may 

 be used as rearing containers. To obtain parasitization a fresh egg card 

 and % of a card from which adults are beginning to emerge should be 

 placed in a container. On the second day another fresh egg card may 

 be placed in with the inoculation card and the first one removed. Thus a 

 sixfold reproduction is obtained. The emergence of the parasities may 

 be concentrated within a short period of time by keeping the parasitized 

 eggs in darkness until emergence begins and then placing them in the 

 light. 



M. E. D. 



References 



Family Psammocharidae 



For the rearing of Psammochares, Anoplius, and Ceropales see p. 517. 

 Family Chrysididae 



For the rearing of members of this family see p. 517. 

 Family Sapygidae 



For the rearing of Sapyga see p. 517. 



Bibliography 



Flanders, S. E. 1930. Recent developments in Trichogramma production. J. 



Econ. Ent. 23:837. 

 1931- The life cycles of Trichogramma minntum in relation to temperature. 



Science 73:458. 

 Hase, A. 1925. Beitrage zur Lebensgeschichte der Schlupfwespe Trichogramma 



evanescent Westwood. Arbeit. Biol. Reichsanstalt fur Land-und Forstwirtschaft 



1925, 14. Band, Heft 2. 

 Wisehart, G. 1929. Large scale production of the egg parasite Trichogramma 



minutum. Canad. Ent. 61:73. 



